TW201931514A - Lift pin system and lift pin assembly for wafer handling - Google Patents

Abstract

The invention discloses a lift pin system and a lift pin assembly. In one or more methods, the lift pin system includes a wafer support, such as an electrostatic chuck or platen, and a lift pin assembly coupled to the wafer support. The lift pin assembly can include a plurality of pins. Each of the plurality of pins can include a tip extending through the housing, a spring disposed within the housing, wherein the spring is biased against the tip and the support arm is coupled to the housing. In some methods, the housing and the support arm can be coupled by threads to enable the tip of each pin to be accessed over the top surface of the wafer support for easy replacement. The replaceable pin tip also allows for easier customization of the pin tip geometry, material, spring force, depending on the particular process and/or wafer characteristics.

Description

Lift pin system for wafer processing

Embodiments of the present invention generally relate to wafer processing and, more particularly, to a customized set-up lift pin system for wafer processing.
The present application claims priority to U.S. Provisional Patent Application Serial No. Serial No. No. No. No. Ser. reference.

Some of the devices formed on the substrate include multilayer films deposited in a deposition chamber such as a physical vapor deposition (PVD) chamber. In some embodiments, the substrate is rotated during the deposition process to achieve good film uniformity. Depositing some of the layers may also include heating the substrate. In addition, the deposition process includes high vacuum pressure. During the deposition process, an electrostatic chuck is typically used to hold the substrate on the substrate support by means of static electricity. During assembly, a substrate (eg, a wafer) supported on three or more lift pins is placed down onto the protrusions or lift pins of the electrostatic chuck. Then, turn on the power or voltage of the electrostatic chuck.

Current lift pin assemblies include the complete removal of one or more of the tips from the process chamber for repair and/or replacement, thus causing tool downtime. In addition, current lift pin assemblies are not customizable and face the problem of defocusing and de-chucking. It is because of these and other deficiencies of the current methods that the present invention is provided.

In a first embodiment, a lift pin system can include: a wafer support; and a lift pin assembly coupled to the wafer support. The lift pin assembly can include a plurality of pins, each of the plurality of pins having a tip extending through the housing, the housing being coupled to the support arm. Each of the plurality of pins can also include a spring located within the housing, the spring biasing against the tip.

In a second embodiment, a lift pin assembly can include a support structure including a plurality of support arms extending through an electrostatic chuck, and a housing coupled to the plurality of support arms. The lift pin assembly can also include a tip extending through the housing and a spring located within the housing, wherein the spring is biased against the tip.

In a third embodiment, a lift pin assembly can include a support structure including a plurality of support arms extending through an electrostatic chuck, and a housing coupled to the plurality of support arms. The lift pin assembly can also include a tip extending through the housing, wherein the tip extends over a top surface of the electrostatic chuck. The lift pin assembly can also include a spring located within the housing, the spring being biased against the tip end.

Various methods in accordance with the present invention will now be described more fully hereinafter with reference to the accompanying drawings in which FIG. The method can be embodied in many different forms and should not be construed as limited to the embodiments described herein. Rather, the embodiments are provided so that this disclosure will be thorough and complete, and the scope of the systems and methods will be fully conveyed to those skilled in the art.

For the sake of convenience and clarity, the terms "top", "bottom", "upper", "lower", "vertical", "level", "horizontal" and "longitudinal" will be used to describe these components and The relative arrangement and orientation of its components relative to the geometry and orientation of the elements of the device appearing in the figures. The terminology will include the words specifically mentioned, their derivatives, and words that have similar meaning and/or meaning.

An element or operation that is singular and "a" or "an" or "an" In addition, the "one embodiment" of the present invention is not intended to be limiting. Additional features may also include such features.

Moreover, in some embodiments, the terms "approximate" or "approximately" are used interchangeably and can be recited using relative metrics that are acceptable to those skilled in the art. For example, these terms can be used to compare with reference parameters to indicate deviations that still provide a predetermined function. Although not limiting, deviations from reference parameters may, for example, be in amounts less than 1%, less than 3%, less than 5%, less than 10%, less than 15%, less than 20%, and the like.

A lift pin system and a lift pin assembly are disclosed. In one or more methods, the lift pin system includes an electrostatic chuck or platen and a lift pin assembly coupled to the electrostatic chuck or platen. The lift pin assembly can include a plurality of pins. Each of the plurality of pins can include a tip extending through the housing and a spring positioned within the housing, wherein the spring is biased against the tip. Each of the plurality of pins can include a support arm coupled to the housing. In some methods, the housing and the support arm can be coupled by threads such that the tip of each pin can be accessed over the top surface of the electrostatic chuck or platen for easy replacement. The replaceable tip further allows for easier customization of the pin tip geometry, material, spring force, etc., depending on the particular process or wafer characteristics.

As will be explained below, a novel lift pin mechanism design for processing wafers on an electrostatic chuck (ESC) is provided herein. The lift pin mechanism can be a replaceable assembly spring loaded with a particular spring and lift pin tip. The lift pin tip can be made of any material that can be welded to the spring. The lift pin tip can actually have any tip geometry depending on the user, process or lift pin use. In one non-limiting embodiment, the lift pins are triangular to prevent the presence of metal on the metal contacts within the housing of the lift pins, thereby reducing particulate generation. The spring provides backside force contact during a direct current (DC) biased radio frequency (RF) plasma process for electrical continuity purposes. In some methods, a spring laser is welded to the lift pin tip to increase the electrical continuity of the DC bias, and the spring can be mechanically clamped (eg, by a screw) to the conductive base of the lift pin tip assembly. The screw can secure the lift pin tip assembly to the conductive lift pin support assembly.

During use, the screw can be accessed over the ESC surface, such as when the support assembly is in the 'up' position of the load/unload wafer. The lift pin tip can include a housing that is screwed or press fit onto the lift pin support assembly. The housing helps shield the lift pin tip out of the plasma line of sight and helps guide the lift pin and spring in a predetermined direction.

In some methods, the spring is disposed within the housing of the lift pin assembly. For example, the bottom tang of the spring can be mechanically clamped to the base inside the housing to maintain electrical continuity and to secure the spring during assembly installation. In other methods, a non-metallic pin tip can be press fit into the weldable pin holder and the weldable pin retainer can be laser welded to the spring.

The lift pin tip can be customized by tool, process, and/or user by varying the geometry and material of the pin tip. For example, to pierce the backside insulation layer, a sharper tip can be selected. Conversely, a flatter tip can be used to avoid damage to the back side. The spring can also be customized depending on the tool, the process, and/or the user, for example, according to a predetermined degree of backside force contact. For example, when piercing the back side insulation layer, a larger spring force can be selected. To avoid damage to the back side of the wafer, a smaller spring force can be selected. The lift pin assembly disclosed herein is intended to operate in a manner that uses a universal support assembly and a replaceable lift pin tip. The lift pin tip can be replaced at a predetermined frequency and/or switched according to the process.

In some embodiments, the tip will be accessible over the ESC/platen/surface so there is no need to access under the chamber and no additional labor/mechanical support/tool downtime is required. The advantage is that it will be possible to remove and install the tip without removing additional parts from the chamber. The lift pin tip assembly also makes the installation process repeatable (for example, to avoid operator error). In one non-limiting example, tool downtime can be reduced from approximately one day to approximately one hour. Embodiments of the invention may also increase the repeatability of the spring force, for example, from 0.3 lbf to 1.8 lbf to 0.45 lbf to 0.55 lbf (or better).

Referring now to Figures 1 through 2, a lift pin system (hereinafter "system") 100 in accordance with an embodiment of the present invention will be explained in greater detail. As shown, system 100 can include a wafer support 102 and a lift pin assembly 104 coupled to wafer support 102. Although not limited to any particular type or geometry, wafer support 102 will be described below as an electrostatic chuck. Electrostatic chucks can hold substrates (eg, semiconductor wafers) in a processing chamber for various applications (eg, physical vapor deposition, etching, or chemical vapor deposition) during substrate handling. In other embodiments, the wafer support 102 can be a platen. The electrostatic chuck can include one or more electrodes embedded within the body of the integrated chuck, the unitary chuck body comprising a dielectric material or a semiconductive ceramic material for creating an electrostatic clamping field. A semiconducting ceramic material (eg, aluminum nitride, boron nitride, or alumina doped with a metal oxide) can be used, for example, to make a Johnsen-Rahbek or non-Coulombic electrostatic clamp field. produce.

In a monopolar electrostatic chuck, the chuck includes a single electrode that is electrically biased relative to the substrate by an applied voltage. Plasma is introduced into the treatment chamber to induce opposing electrostatic charges in the chuck and substrate to form an electrostatic attraction to hold the substrate to the chuck by static electricity. In a bipolar electrostatic chuck, the chuck includes two electrodes that are electrically biased relative to each other to provide an electrostatic force to hold the substrate to the chuck. Unlike a monopolar electrostatic chuck, a bipolar chuck does not require the presence of plasma to create an electrostatic clamping force.

Electrostatic chucks have several advantages over mechanical clamping devices and vacuum chucks. For example, electrostatic chucks reduce stress-induced cracking caused by mechanical clamping, allowing larger areas of the substrate to be exposed for disposal (nearly excluding or not excluding edges) and useful in low pressure or high vacuum environments. In addition, the electrostatic chuck can hold the substrate more evenly to the surface of the chuck to allow for greater control of the substrate temperature. This control can be further enhanced by using a heat transfer gas to effect thermal coupling between the chuck and the substrate.

The various processes used to make the integrated circuit can include high temperature and wide temperature ranges for substrate handling. These temperatures may range from about 20 ° C to about 150 ° C, and may be as high as 300 ° C to 500 ° C, or higher for some processes. Therefore, it is generally desirable to have an electrostatic chuck that can operate over a wide temperature range.

To take advantage of the electrostatic chuck, the electrostatic chuck can be formed as part of a substrate support assembly that includes various components for heating and cooling the substrate and for routing power to the chuck electrodes. Additionally, the substrate support assembly can also include elements for providing substrate bias and for providing plasma power. Thus, the ceramic body of the electrostatic chuck can include additional electrodes and other components such as heating elements, gas passages, and coolant passages. Additionally, the electrostatic chuck can be attached to one or more support members.

Still referring to FIGS. 1-2, the lift pin assembly 104 of the system 100 can further include a support structure 106 that includes a plurality of support arms 108, 110, and 112 that extend from the support base 114. As shown, the plurality of support arms 108, 110, and 112 extend into the wafer support 102, for example, through the opening 123. While not limited to any particular shape or configuration, the support base 114 can include three (3) points, each of which includes a corresponding support arm at one end thereof. In some embodiments, the plurality of support arms 108, 110, and 112 are formed integrally with the support base 114. The support base 114 can include a top surface 115 that is configured to abut or position directly adjacent the bottom surface 117 of the wafer support 102 depending on the raised or lowered position of the lift pin assembly 104. The support base 114 can also include a fastener 119 that couples the support base 114 to the shaft member 121. In some embodiments, the support base 114 is rotatable about the shaft member 121.

As further shown, pin 116, pin 118, and pin 120 are coupled to each of the plurality of support arms 108, 110, and 112, respectively. In some embodiments, each of the plurality of pins 116, 118, and 120 can be directly and physically coupled to each of the respective support arms 108, 110, and 112, such as by threads. In particular, in some embodiments, the internal threads along each of the plurality of pins 116, 118, and 120 are mechanically coupled to the outside of the respective support arms 108, 110, and 112. Thread.

Referring now to Figures 3 through 4, an exemplary pin 116 of a lift pin assembly 104 in accordance with a non-limiting embodiment of the present invention will be explained in greater detail. As shown, the pin 116 can include a housing 128 having a proximal end 130 and a distal end 132. The tip 134 can extend through an opening 136 located in the distal end 132 of the housing 128. At the proximal end 130, the housing 128 can be coupled and mechanically coupled directly to the support arm 108. In some embodiments, the tip 134 includes a first section 138 that extends beyond the housing 128 for engagement with a wafer (not shown). The tip 134 can also include a second section 140 located within the housing 128 that includes a flange 142 having a cross-section or diameter that is larger/longer than the diameter of the opening 136. As such, the flange 142 can constrain the axial movement of the pin toward the distal end 132 of the housing 128.

As further shown, the pin 116 can include a spring 144 located within the interior 146 of the housing 128. In some embodiments, the spring 144 is a helical spring having a first end 148 that surrounds the second section 140 of the tip 134 and is contiguous with the flange 142. In some embodiments, the spring 144 can be welded directly to the tip 134. The second end 150 of the spring 144 can be coupled to a base 152 located within the housing 128. For example, the base 152 can include a first portion 154 that extends toward the distal end 132 of the housing 128 into the spring 144. The base 152 can also include a second portion 156 extending from the first portion 154, the second portion 156 having a larger cross-section than the first portion 154 to engage the inner shoulder 160 of the housing 128 to maintain the base 152 in the housing The axial position within the interior 146 of 128.

In some embodiments, the second end 150 of the spring 144 can be physically coupled to the base 152 directly. For example, the bottom tang 162 of the spring 144 can extend within the inner passage 164 of the base 152 and extend around the stem 166 of the fastener 168 (eg, a screw). In some embodiments, the fastener 168 and the base 152 can mechanically clamp the bottom tang 162 to maintain electrical continuity and secure the spring 144 in place during installation of the pin 116.

Referring now to Figure 5, another exemplary pin 216 of a pin assembly (e.g., lift pin assembly 104 of Figures 1-4) in accordance with a non-limiting embodiment of the present invention will be explained in greater detail. As shown, the pin 216 can include a housing 228 having a proximal end 230 and a distal end 232. The tip 234 can extend through an opening 236 located in the distal end 232 of the housing 228. At the proximal end 230, the housing 228 can be coupled and mechanically coupled directly to the support arm 208. In this embodiment, the housing 228 can be press fit around the support arm 208 and includes one or more O-rings 280 on the inner surface of the housing 228 and the support arms 208. A friction seal is formed between the outer surfaces.

In some embodiments, the tip 234 includes a first section 238 that extends beyond the housing 228 to engage a wafer (not shown). The tip 234 can also include a second section 240 located within the housing 228 that includes a flange 242 having a cross-section or diameter that is larger/longer than the diameter of the opening 236. As such, the flange 242 can constrain the axial movement of the pin toward the distal end 232 of the housing 228. In this embodiment, the first section 238 and the second section 240 can be separate components that are coupled together. Moreover, in some embodiments, the first section 238 can be non-metallic/non-conductive. The first section 238 is press fit into the second section 240 and the second section 240 is laser welded to the spring 244.

As further shown, the pin 216 can include a spring 244 located within the interior 246 of the housing 228. In some embodiments, the spring 244 is a helical spring having a first end 248 that surrounds the second section 240 of the tip and is contiguous with the flange 242. The second end 250 of the spring 244 can be coupled to a base 252 located within the housing 228. For example, the base 252 can include a first portion 254 that extends toward the distal end 232 of the housing 228 into the spring 244. The base 252 can also include a second portion 256 extending from the first portion 254, the second portion 256 having a larger cross-section than the first portion 254 to engage the inner shoulder 260 of the housing 228 to maintain the base 252 in the housing The axial position within the interior 246 of 228.

In some embodiments, the second end 250 of the spring 244 can be directly coupled to the base 252 directly. For example, the bottom tang 262 of the spring 244 can extend within the inner passage 264 of the base 252 and extend around the stem 266 of the fastener 268 (eg, a screw). In some embodiments, the fastener 268 and the base 252 can mechanically clamp the bottom tang 262 to maintain electrical continuity and secure the spring 244 in place during installation of the pin 216.

Referring now to Figures 6 through 7, a lift pin system (hereinafter "system") 300 in accordance with an embodiment of the present invention will be explained in greater detail. As shown, system 300 can include a wafer support 302 and a lift pin assembly 304 coupled to wafer support 302. Although not limited to any particular type or geometry, the wafer support 302 can be an electrostatic chuck, or a platen, for holding a substrate (eg, a semiconductor wafer).

The lift pin assembly 304 of the system 300 can also include a support structure 306 that includes a plurality of support arms 308, 310, and 312 that extend from the support base 314. As shown, the plurality of support arms 308, 310, and 312 extend into the wafer support 302, for example, through a set of openings 323. While not limited to any particular shape or configuration, the support base 314 can include three (3) points, each of which includes a corresponding support arm at one end thereof. The support base 314 can include a top surface 315 that is configured to abut or position directly adjacent the bottom surface 317 of the wafer support 302 depending on the raised or lowered position of the lift pin assembly 304. The support base 314 can also include a plurality of fasteners (eg, screws) 319 that couple the support base 314 to the base 327 and the shaft 321 . In some embodiments, the support base 314 can be rotated about the shaft member 321.

As further shown, pin 316, pin 318, and pin 320 are coupled to each of the plurality of support arms 308, 310, and 312, respectively. In some embodiments, each of the plurality of pins 316, 318, and 320 can be directly/physically coupled to each of the corresponding support arms 308, 310, and 312, such as by threads or by press fit. Each of the corresponding support arms 308, 310, and 312 is coupled. In particular, in some embodiments, internal threads along each of the plurality of pins 316, 318, and 320 are mechanically coupled to external threads along the outside of respective support arms 308, 310, and 312 . As best shown in FIG. 7, each of the plurality of pins 316, 318, and 320 can include one or more processing flats 331 to enable removal from the support base 314.

Referring now to Figure 8, an exemplary pin 316 of a lift pin assembly 304 in accordance with a non-limiting embodiment of the present invention will be explained in greater detail. As shown, the pin 316 includes a housing 328 having a proximal end 330 and a distal end 332. In some embodiments, the proximal end 330 can extend to the top surface 315 of the support base 314 (Figs. 6-7). The tip 334 can extend through an opening 336 located in the distal end 332 of the housing 328. At the proximal end 330, the housing 328 can be coupled and mechanically coupled directly to the support arm 308. In some embodiments, the tip 334 includes a first section 338 that extends beyond the housing 328 to engage a wafer (not shown). The tip 334 can also include a second section 340 located within the housing 328 that includes a flange 342 having a cross-section or diameter that is larger/longer than the diameter of the opening 336. As such, the flange 342 prevents the tip 334 from slipping out of the distal end 332 of the housing 328. In some embodiments, the first section 338 can be press fit into the second section 340. As shown, the second section 340 can be a shaft that extends through the interior 346 of the housing 328. The second section 340 can have a proximal end 372 proximate the support arm 308 and a distal end 374 that extends to the distal end 332 of the housing 328. The second section 340 can include a second flange 376 that abuts the inner shoulder 380 to constrain the movement of the pin 316.

As further shown, the pin 316 can include a spring 344 located within the interior 346 of the housing 328. In some embodiments, the spring 344 is a helical spring having a first end 348 that surrounds the second section 340 of the tip 334 and is contiguous with the second flange 376. In some embodiments, the spring 344 can be welded directly to the second section 340 of the tip 334. The second end 350 of the spring 344 can abut the support arm 308 that extends into the housing 328. In some embodiments, the support arm 308 can include a support stem 382 that extends upward into the second end 350 of the spring 344.

In some embodiments, the second end 350 of the spring 344 can be directly coupled to the support arm 308. Although not specifically shown, the bottom tang of the spring 344 can extend within the inner passage of the support arm 308. The bottom tang of the spring 344 can be mechanically clamped or otherwise retained in the inner passage to ensure electrical continuity. The pin 316 can be press fit and screwed into place for use in the field such that the pin 316 is essentially an inseparable assembly.

A first advantage of the embodiments herein includes the ease with which the pin tip can be replaced, as the pin tip can be replaced over the surface of the electrostatic chuck during conventional handling, thus reducing downtime. A second advantage of the embodiments herein is the ability to use different lift pins for different processes/categories, different devices/wafers (backside layers), and temperature ranges. The lift pins can be customized for the process, user and product line. A third advantage of the embodiments herein includes a targeted improvement in that the lift pins are replaced more reproducibly and more easily. A fourth advantage of the embodiments herein includes reducing the suction cup detachment problem by providing a customized material and lifting pin force.

Although certain embodiments of the invention have been described herein, the invention is not limited thereto, as the scope of the invention is to be construed as the same as the scope of the invention. Therefore, the above description should not be considered as limiting. Rather, the above description is merely illustrative of specific embodiments. Other refinements within the scope and spirit of the appended claims will be apparent to those skilled in the art.

100, 300‧‧‧ Lifting pin system/system

102, 302‧‧‧ wafer support

104, 304‧‧‧ Lifting pin assembly

106, 306‧‧‧Support structure

108, 110, 112, 208, 308, 310, 312‧‧‧ support arms

114, 314‧‧‧ Support base

115, 315‧‧‧ top surface

116, 118, 120, 216, 316, 318, 320‧‧ ‧ sales

117, 317‧‧‧ bottom surface

119, 168, 268, 319‧‧‧ fasteners

121, 321‧‧‧ shaft parts

123, 136, 236, 323, 336‧‧

128, 228, 328‧‧‧ shell

130, 230, 330, 372‧‧ ‧ near end

132, 232, 332, 374‧‧‧ remote

134, 234, 334‧‧‧ cutting-edge

138, 238, 338‧‧‧ first section

140, 240, 340‧‧‧ second section

142, 242, 342‧ ‧ flange

144, 244, 344‧‧ springs

146, 246, 346‧‧‧ internal

148, 248, 348‧‧‧ first end

150, 250, 350‧‧‧ second end

152, 252‧‧‧ pedestal

154, 254‧‧‧ part one

156, 256‧‧‧ Part II

160, 260, 380 ‧ ‧ shoulder

162, 262‧‧‧ bottom tang

164, 264‧‧

166, 266‧‧ ‧ trunk

280‧‧‧O-ring

327‧‧‧Base

331‧‧‧Processed flat material

376‧‧‧second flange

382‧‧‧Supporting the trunk

1 shows a side cross-sectional view of a lift pin system in accordance with certain aspects of the present disclosure.

2 illustrates a perspective view of a lift pin assembly of the lift pin system of FIG. 1 in accordance with certain aspects of the present disclosure.

3 illustrates a side cross-sectional view of the pin of the lift pin system of FIG. 1 in accordance with certain aspects of the present disclosure.

4 illustrates another side cross-sectional view of the pin of the lift pin system of FIG. 1 in accordance with certain aspects of the present disclosure.

Figure 5 illustrates a side cross-sectional view of another pin in accordance with certain aspects of the present disclosure.

6 shows a side cross-sectional view of a lift pin system in accordance with certain aspects of the present disclosure.

Figure 7 illustrates a perspective view of the lift pin assembly of the lift pin system of Figure 6 in accordance with certain aspects of the present disclosure.

Figure 8 illustrates a side cross-sectional view of the pin of the lift pin system of Figure 6 in accordance with certain aspects of the present disclosure.

The schema is not necessarily proportionate. The drawings are merely representations and are not intended to describe specific parameters of the invention. In addition, the drawings are intended to depict exemplary embodiments of the invention and are not to be considered as limiting.

In addition, some of the elements in the figures may be omitted or not to scale. For clarity of description, the cross-sectional view may be in the form of a "fragment" or may be a "myopia" cross-sectional view, thereby omitting some of the background lines that are observable in the "real" cross-sectional view. In addition, some reference numbers may be omitted in some drawings for clarity.

Claims (15)

A lift pin system comprising: Wafer support; a lift pin assembly coupled to the wafer support, the lift pin assembly including a plurality of pins, the plurality of pins comprising: a tip extending through the housing, the housing being coupled to the support arm; and A spring is located within the housing and the spring is biased against the tip. The pin lifting system of claim 1, wherein the plurality of pins extend through the wafer support. The pin lifting system of claim 1, wherein the support arm is threadably coupled to the housing. The pin lifting system of claim 1, further comprising a fastener located within the housing, wherein the spring is coupled to the fastener. The pin lifting system of claim 4, wherein the tip comprises: a first section extending through an opening of the housing; A second section extending from the first section, the second section being located within the housing. The pin lifting system of claim 5, wherein the second section comprises a flange, and wherein the first end of the spring abuts the flange. The pin lifting system of claim 5, further comprising a base located within the housing, wherein the second end of the spring is directly coupled to the base. The pin lifting system of claim 6, wherein the first end of the spring extends around the second section of the tip. The pin lifting system of claim 7, wherein the second end of the spring is coiled on a stem of the fastener. The pin lifting system of claim 8, wherein the base comprises: a first portion extending into the spring toward the tip; A second portion extending from the first portion, the second portion having a larger cross section than the first portion for engaging an inner shoulder of the housing. A lift pin assembly comprising: a support structure comprising a plurality of support arms extending through the electrostatic chuck; a housing coupled to the plurality of support arms; a tip extending through the housing; A spring is located within the housing and the spring is biased against the tip. The pin lifting assembly of claim 11, wherein the tip extends over a top surface of the electrostatic chuck, and wherein the plurality of support arms are directly coupled to the housing by threads. The pin lifting assembly of claim 11, further comprising a screw located within the housing, wherein the spring is coupled to the screw. The pin lifting assembly of claim 11, wherein the tip comprises: a first section extending through an opening at a distal end of the housing; a second section extending from the first section, the second section being located within the housing, wherein the second section includes a flange adjacent an inner surface of the distal end of the housing And wherein the first end of the spring abuts the flange. A lift pin assembly comprising: a support structure comprising a plurality of support arms extending through the electrostatic chuck; a housing coupled to the plurality of support arms; a tip extending through the housing, wherein the tip extends over a top surface of the electrostatic chuck; A spring is located within the housing and the spring is biased against the tip.